New temperate seaweed targets for mitigation of ruminant methane emissions: an in vitro assessment

Figures & data

Table 1. Collection sites of seaweed specimens used for this study. All locations were within the North Island, New Zealand.

Species	Collection site	GPS co-ordinates	Collection date	Depth (m)
Asparagopsis armata	Mathesons Bay	36.31°S, 174.80°E	Oct 2019	2–3
Bonnemaisonia hamifera	Mathesons Bay	36.31°S, 174.80°E	Oct 2019	2–3
Euptilota formisissima	Tauranga harbour	37.60°S, 176.05°E	Dec 2019	4–7
Plocamium cirrhosum	Makara Beach	41.22°S, 174.71°E	Jan 2020	6–7
Vidalia colensoi	Papatea Bay	37.64°S, 177.84°E	Nov 2019	1–2
Ecklonia radiata	Motuotau Island	41.27°S, 173.14°E	Dec 2019	3–5
Ulva species B (WELT A027378; sp. 1 sensu Heesch et al., 2009)^1	Cultivated biomass	37.60°S, 176.05°E	Dec 2019	N/A

1 Nelson et al., 2019.

Figure 1. Mean (± SE, n = 3) (a) total gas (TGP), (b) CH₄, and (c) H₂ production (ml g^–1), and (d) degradability of organic matter (OMdeg, % degraded) at the end of in vitro incubations for freeze-dried perennial ryegrass (RG299, negative control), and seaweed species Asparagopsis armata (ASP, positive control), Bonnemaisonia hamifera (BNM), Euptilota formisissima (EPT), Plocamium cirrhosum (PLC), Vidalia colensoi (VDA), Ecklonia radiata (ECK), and Ulva sp. B (ULVA) at inclusion levels of 2%, 6%, and 10% (OM-based) (24 h data).*Indicates treatment significantly different (p < 0.05) from control according to PERMANOVA.

Table 2. Elemental composition (wt%) of carbon (C), hydrogen (H), nitrogen (N), sulphur (S), bromine (Br), chlorine (Cl), and iodine (I), and concentration (mg/g DW) of bromoform (BF) for seaweed species Asparagopsis armata (ASP, positive control), Bonnemaisonia hamifera (BNM), Euptilota formisissima (EPT), Plocamium cirrhosum (PLC), Vidalia colensoi (VDA), Ecklonia radiata (ECK), and Ulva sp. B (ULVA).

Seaweed	C	H	N	S	Br	Cl	I	BF
ASP	19.5	3.0	2.7	2.8	7.1	14.8	1.0	10.4
BNM	20.8	3.5	2.3	3.0	1.6	17.0	0.8	–
EPT	17.0	3.0	2.6	2.4	0.7	13.3	0.0	–
PLC	25.1	4.0	3.5	5.1	1.3	9.5	0.1	–
VDA	32.6	4.7	2.7	3.0	3.9	5.9	0.0	–
ECK	32.3	5.0	1.6	1.2	0.1	8.0	0.4	–
ULVA	33.8	4.0	3.7	3.4	0.1	4.4	0.0	–

Table 3. Composition (%DW) of organic matter (OM), ash, crude protein (CP), crude fat (CF), acid detergent fibre (ADF), neutral detergent fibre (NDF), soluble sugars, starch, and polyphenols (PP) (mg/g DW) for perennial ryegrass (negative control), and seaweed species Asparagopsis armata (ASP, positive control), Bonnemaisonia hamifera (BNM), Euptilota formisissima (EPT), Plocamium cirrhosum (PLC), Vidalia colensoi (VDA), Ecklonia radiata (ECK), and Ulva sp. B (ULVA).

Seaweed	OM	ASH	CP	CF	ADF	NDF	Soluble sugars	Starch	PP
Control	90	10	16.8	2.0	22.4	44.4	9.1	1.2	–
ASP	44	56	15.2	<0.5	9.7	24.8	1.5	<0.5	3.4
BNM	49	51	11.7	<0.5	5.2	30.0	3.2	2.1	2.5
EPT	49	51	13.3	<0.5	19.9	40.4	1.3	1.8	3.0
PLC	60	40	17.9	<0.5	8.5	38.2	2.0	1.5	2.6
VDA	72	28	13.8	<0.5	12.7	41.5	2.3	5.7	10.6
ECK	75	25	7.2	<0.5	7.2	26.9	2.0	<0.5	55.3
ULVA	80	20	19.0	<0.5	12.6	30.2	1.6	7.7	2.1

-Indicates not detected

Table 4. Effect of seaweed species Asparagopsis armata (ASP, positive control), Bonnemaisonia hamifera (BNM), Euptilota formisissima (EPT), Plocamium cirrhosum (PLC), Vidalia colensoi (VDA), Ecklonia radiata (ECK), and Ulva sp. B (ULVA) (mean ± SE, n = 3) at inclusion levels of 0% (perennial ryegrass, negative control), 2%, 6%, and 10% (OM-based) on total (mmolg^–1) and individual volatile fatty acid (VFA) (% total) production at the end of in vitro incubations (48 h data).

Seaweed	Seaweed inclusion (%) OM)	Total VFA [mmol/g]	AC (%)	PR (%)	BU (%)	VA (%)	ISB (%)	ISV (%)
Control	0	6.7 ± 0.1^B	66.6 ± 0.4^B	19.1 ± 0.4^B	10.3 ± 0.1^B	1.2 ± 0.1^B	1.0 ± 0.0	1.7 ± 0.1
ASP	2	5.2 ± 0.2^A	51.4 ± 0.3^A	28.1 ± 0.6^A	16.3 ± 0.3^A	2.0 ± 0.3^A	0.7 ± 0.1	1.0 ± 0.1
BNM	2	6.6 ± 0.2^B	62.1 ± 1.1^C	21.9 ± 1.2^B	11.9 ± 0.3^C	1.4 ± 0.0	0.9 ± 0.1	1.5 ± 0.2
	6	5.3 ± 0.1^A	53.1 ± 0.4^A	28.5 ± 0.4^A	14.5 ± 0.3^C	1.9 ± 0.2	0.7 ± 0.1	1.1 ± 0.0
	10	5.0 ± 0.1^A	52.6 ± 0.5^A	29.2 ± 0.6^A	14.4 ± 0.3^C	1.9 ± 0.2	0.7 ± 0.1	1.0 ± 0.1
EPT	2	6.5 ± 0.1^B	64.5 ± 0.4^C	20.6 ± 0.5^B	10.8 ± 0.2^C	1.3 ± 0.0	1.0 ± 0.0	1.7 ± 0.1
	6	5.9 ± 0.1^C	61.2 ± 0.7^C	22.9 ± 0.8^C	12.0 ± 0.4^C	1.4 ± 0.1	0.9 ± 0.1	1.5 ± 0.2
	10	5.8 ± 0.2^C	60.2 ± 0.6^C	24.3 ± 0.7^C	12.0 ± 0.3^B	1.3 ± 0.0	0.8 ± 0.0	1.3 ± 0.1
PLC	2	6.6 ± 0.1^B	66.3 ± 0.3^B	19.3 ± 0.4^B	10.4 ± 0.2^B	1.2 ± 0.0	1.0 ± 0.0	1.7 ± 0.1
	6	6.3 ± 0.2^C	64.5 ± 0.6^C	20.7 ± 0.6^B	10.8 ± 0.2^C	1.2 ± 0.0	1.0 ± 0.0	1.7 ± 0.1
	10	5.9 ± 0.2^C	61.2 ± 1.0^C	23.1 ± 1.1^C	12.1 ± 0.3^C	1.3 ± 0.0	0.8 ± 0.1	1.3 ± 0.2
VDA	2	6.6 ± 0.1^B	66.7 ± 0.4^B	18.8 ± 0.6^B	10.5 ± 0.3^B	1.2 ± 0.0	1.0 ± 0.0	1.7 ± 0.1
	6	6.2 ± 0.1^C	66.6 ± 0.5^B	19.0 ± 0.6^B	10.4 ± 0.5^B	1.3 ± 0.1	1.0 ± 0.0	1.6 ± 0.1
	10	6.1 ± 0.2^C	66.0 ± 0.7^B	19.1 ± 0.7^B	10.8 ± 0.5^B	1.5 ± 0.0	0.9 ± 0.0	1.5 ± 0.1
ECK	2	6.7 ± 0.1^B	66.8 ± 0.2^B	19.5 ± 0.5^B	9.9 ± 0.3^B	1.1 ± 0.1	1.0 ± 0.0	1.7 ± 0.1
	6	6.4 ± 0.2^B	66.2 ± 0.3^B	21.0 ± 0.4^C	9.5 ± 0.3^B	1.0 ± 0.1	0.9 ± 0.0	1.4 ± 0.1
	10	6.2 ± 0.1^C	65.0 ± 1.6^B	22.1 ± 1.0^C	9.5 ± 0.5^B	1.1 ± 0.2	0.8 ± 0.1	1.2 ± 0.2
ULVA	2	6.8 ± 0.1^B	66.9 ± 0.3^B	19.1 ± 0.5^B	10.1 ± 0.2^B	1.2 ± 0.0	1.0 ± 0.0	1.7 ± 0.1
	6	6.5 ± 0.1^B	66.6 ± 0.3^B	19.0 ± 0.6^B	10.2 ± 0.3^B	1.2 ± 0.0	1.1 ± 0.0	1.8 ± 0.1
	10	6.3 ± 0.1^C	66.7 ± 0.4^B	19.0 ± 0.6^B	10.0 ± 0.3^B	1.2 ± 0.0	1.1 ± 0.0	1.9 ± 0.1

Data were analysed separately for each species of seaweed. Treatment is significantly (p < 0.05) different from the ^Acontrol (0%), ^BASP 2%, or ^Cboth according to PERMANOVA. Acetate (AC), propionate (PR), butyrate (BU), valerate (VA), isobutyrate (ISB), isovalerate (ISV).

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